Separating machine

A separating machine comprising a plurality of rotors (20) provided in a frame (10) such that axes of said rotors are arranged parallel to one another from a supply side where objects to be screened (W) including mixed substances different at least in size are supplied from above by a conveying means (C1) to a discharge side where the remainders after screening are discharged, a series of rotors (20) being arranged in an inclined plane with a series of said rotors (20) on the discharge side being placed partially higher than those on the supply side and the inclined plane having at least one raised area (4C) provided between said discharge and supply sides, and such that said rotors (20) are rotated in the same direction by a rotating drive means (30) to feed the objects to be screened from the supply side to the discharge side, and each rotor (20) further comprises a plurality of large diameter sections (25) and a plurality of small diameter sections (28) alternately disposed in the axial direction of each rotor (20) and arranged in a staggered relation in the feeding direction to define screening gaps (G) having desired dimensions between said large and small diameter sections (25-28), and each of said large diameter sections (25) of said rotor (20) has a plurality of projections (26a) at least on one side, which do not interfere with said large diameter sections (25) and said small diameter sections (28) of adjacent rotors (20).